Electric compressor

ABSTRACT

An electric compressor includes: a driving part being a driving source configured to generate a rotating force of the electric compressor, the driving part including a stator; a motor housing surrounding the driving part, the motor housing including: one or more first mounting lugs installed on an outer surface of the motor housing; and a press fitting portion formed on an inner surface of the motor housing, the stator of the driving part is press fitted into the press fitting portion; a rear housing surrounding a compressing part configured to rotate due to a rotational driving force generated by the driving part so as to compress a refrigerant; and a center housing installed between the motor housing and the rear housing, wherein the first mounting lugs are installed spaced at a first distance from a center of gravity of the electric compressor overlapping with the press fitting portion.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 10-2018-0149816, filed on Nov. 28, 2018, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND Field of the Invention

The present invention relates to an electric compressor.

Discussion of Related Art

Generally, various types of compressors which serve to compress refrigerants in vehicle cooling systems have been developed.

Recently, electric compressors are actively being developed. The electric compressor is divided into a driving part, a compressing part, and a control unit.

In this case, the driving part includes a driving part housing forming an exterior thereof and a stator and rotor which are installed around the same shaft in the driving part housing.

The compressing part includes a compressing part housing forming an exterior thereof and coupled to a rear end of the driving part housing and rotating and fixed scrolls which are mounted to relatively rotate in the compressing part housing.

The control unit includes a cover housing forming an exterior thereof and coupled to a front end of the driving part housing and includes a printed circuit board (PCB), various driving circuits, and elements which are mounted in the cover housing.

In a case in which a refrigerant is compressed by the electric compressor, external power is applied to the control unit. In this case, the control unit transmits an operating signal to the driving part.

When the operating signal is transmitted to the driving part, an electromagnet type stator press-fitted into an inner circumferential surface of the driving part housing is excited to have magnetic properties, and accordingly, the driving part rotates a rotor at a high speed using an electromagnetic interaction with the rotor.

In this case, when a rotating shaft of the driving part rotates at a high speed, the rotating scroll of the compressing part coupled to a rear end of the rotating shaft is synchronized with the rotation of the rotating shaft and rotated at a high speed. The compressing part interacts with the fixed scroll matched with the rotating scroll in a state in which the rotating scroll faces the fixed scroll to compress the refrigerant from an outer circumference of a scroll to a central portion of the scroll at a high pressure, wherein the refrigerant flows from the driving part to the compressing part. A compressing operation of the refrigerant is completed through a series of processes.

As illustrated in FIG. 1, a conventional electric compressor includes a motor part 10, a control unit 20, and a scroll compressing part 30.

The motor part 10 generates a rotating force. The control unit 20 controls operation of the motor part 10. A fixed scroll 31 and a rotating scroll 32 are embedded in the scroll compressing part 30.

The scroll compressing part 30 includes one or more mounting lugs 33 which fix the compressor to a vehicle body so as to reduce amounts of vibrations and noises generated when the rotating scroll 32 operates. In the conventional electric compressor, the mounting lugs are installed on an outer circumferential surface of the scroll compressing part 30 to reduce the amount of vibrations.

However, a total force between the fixed scroll 31 and the rotating scroll 32 is designed to be zero, and thus it is difficult to consider the scroll compressing part 30 as a major vibration source.

In addition, as illustrated in FIG. 1, in a case in which the number of the mounting lugs is designed to be six, since a weight of an electric compressor is increased and a time period for which the electric compressor is installed in a vehicle is also increased, there is a problem in that productivity is lowered.

SUMMARY OF THE INVENTION

The present invention is directed to providing an electric compressor capable of minimizing an amount of vibrations transmitted to a vehicle body by optimizing a position of a mounting lug of a medium electric compressor.

According to exemplary embodiments of the present invention, an electric compressor includes: a driving part being a driving source configured to generate a rotating force of the electric compressor, the driving part including a stator; a motor housing surrounding the driving part, the motor housing including: one or more first mounting lugs installed on an outer surface of the motor housing; and a press fitting portion formed on an inner surface of the motor housing, the stator of the driving part is press fitted into the press fitting portion; a rear housing surrounding a compressing part configured to rotate due to a rotational driving force generated by the driving part so as to compress a refrigerant; and a center housing installed between the motor housing and the rear housing, wherein the first mounting lugs are installed spaced at a first distance from a center of gravity of the electric compressor and overlapping with the press fitting portion.

The first mounting lugs of the motor housing may be installed as far away as possible from the center of gravity of the electric compressor within the range of the press fitting portion.

The first mounting lugs of the motor housing may be installed to be spaced at a second distance from each other on the outer surface of the motor housing.

The first mounting lugs of the motor housing may be symmetrically installed to be collinear with each other on motor housing.

The rear housing may include: one or more second mounting lugs installed on an outer surface of the rear housing, the mounting lugs being installed to be spaced at a third distance from the center of gravity of the electric compressor.

The second mounting lugs may be installed as far away as possible from the center of gravity of the electric compressor.

The mounting lugs of the rear housing may be installed to be spaced at a fourth distance from each other on the outer surface of the rear housing.

The second mounting lugs of the rear housing may be symmetrically installed to be collinear with each other on the rear housing.

The first mounting lugs of the motor housing may be formed to have a cylindrical shape, and the second mounting lugs of the rear housing may be formed to have a cylindrical shape.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view illustrating an overall structure of a general electric compressor;

FIG. 2 is a front view illustrating an electric compressor according to an exemplary embodiment of the present invention; and

FIG. 3 is a perspective view illustrating a motor housing included in the electric compressor according to the exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Advantages and features of the present invention and methods of achieving the same will be clearly understood with reference to the following embodiments and the accompanying drawings. However, the present invention is not limited to the embodiments to be disclosed below and may be implemented in various different forms. The embodiments are provided in order to fully explain the present invention and fully explain the scope of the present invention for those skilled in the art. The scope of the present invention is only defined by the appended claims. Meanwhile, the terms used herein are provided only to describe the embodiments of the present invention and not for purposes of limitation. Unless the context clearly indicates otherwise, the singular forms include the plural forms. It will be understood that the terms “comprise” or “comprising,” when used herein, specify some stated components, steps, operations and/or elements, but do not preclude the presence or addition of one or more other components, steps, operations and/or elements.

Hereinafter, embodiments of the present invention will be described with reference to accompanying drawings in detail. FIG. 2 is a front view illustrating an electric compressor according to the present invention, and FIG. 3 is a perspective view illustrating a motor housing include in the electric compressor according to the present invention.

As illustrated in FIG. 2, an electric compressor 100 of the present invention includes a motor part configured to generate a rotating force, a control unit configured to control operation of the motor part, and a scroll compressing part in which a fixed scroll and a rotating scroll are embedded.

A motor housing 200 surrounding a driving part configured to generate a rotating force of the electric compressor, a rear housing 300 surrounding the compressing part rotated due to a rotational driving force of the driving part to compress a refrigerant, and a center housing 400 installed between the motor housing 200 and the rear housing 300 are formed outside the electric compressor 100.

The electric compressor 100 according to the present invention optimizes positions of mounting lugs 220 and 320 installed in the motor housing 200 and the rear housing 300 to minimize an amount of vibrations transmitted to a vehicle body.

More specifically, in the electric compressor 100, a rotating force M is generated around a center of gravity of the electric compressor due to a gas force of the refrigerant in the compressing part.

Since forces F1 and F2 at lower ends of the mounting lugs 220 and 320 are calculated by dividing a rotating force by distances from the center of gravity of the electric compressor to the lower ends of the mounting lugs 220 and 320, in order to minimize magnitudes of vibration at the lower ends of the mounting lugs 220 and 320, magnitudes of the forces applied to the mounting lugs 220 and 320 should be minimized. To this end, the electric compressor needs to be designed so that the distances from the center of gravity M to the lower ends of the mounting lugs 220 and 320 are maximized.

The motor housing 200 surrounds the driving part configured to supply a rotating force of the electric compressor 100. The motor housing 200 is formed to have a hollow shape, and four to eight ribs 210 are formed on an inner circumferential surface of the motor housing 200 along a circumference of the motor housing 200.

That is, in the motor housing 200, the plurality of ribs 210 are formed on the inner circumferential surface of motor housing 200 to accommodate components such as a motor therein and also prevent deformation of the center housing 400.

In addition, one or more mounting lugs 220 of the motor housing are mounted on an outer surface of the motor housing 200.

In this case, the mounting lugs 220 of the motor housing 200 are installed to be spaced a gap from the center of gravity M of the electric compressor 100 within a range of a motor stator press fitting portion 230, and installing the mounting lugs 220 of the motor housing as far away as possible from the center of gravity M of the electric compressor within the range of the motor stator press fitting portion 230 is effective. In other words, the mounting lugs 220 of the motor housing 200 are installed to overlap with the motor stator press fitting portion 230.

In this case, the mounting lugs 220 of the motor housing are installed within the range of the motor stator press fitting portion 230 so as to obtain a secondary effect in that a motor stator is prevented from being separated therefrom.

That is, when the motor stator press fitting portion 230 is strengthened by positioning the mounting lugs 220 of the motor housing on the motor stator press fitting portion 230 of the motor housing 200, the motor stator is prevented from being separated therefrom.

In addition, the mounting lugs 220 of the motor housing are installed to be spaced a gap from each other on the outer surface of the motor housing 200. In the present invention, the mounting lugs 220 of the motor housing are symmetrically installed to be collinear with each other on the motor housing 200.

In the present invention, the mounting lugs 220 of the motor housing 200 are formed to have a cylindrical shape, but the mounting lugs 220 of the motor housing 200 may be variously changed according to an environment and a purpose.

The rear housing 300 is rotated due to a rotational driving force of the driving part to surround the compressing part configured to compress the refrigerant.

One or more mounting lugs 320 of the rear housing are installed on an outer surface of the rear housing 300.

In this case, the mounting lugs 320 of the rear housing are installed to be spaced a gap from the center of gravity M of the electric compressor. Installing the mounting lugs 320 of the rear housing as far away as possible from the center of gravity M of the electric compressor is effective.

The mounting lugs 320 of the rear housing are installed to be spaced a gap from each other on the outer surface of the rear housing 300. In the present invention, the mounting lugs 320 of the rear housing are symmetrically formed to be collinear with each other on the rear housing 300.

In this case, in the mounting lugs 320 of the rear housing, hindrance between the mounting lug of the rear housing and a discharge port may occur according to a position of the discharge port. One of the mounting lugs 320 of the rear housing may move toward the center of gravity M of the electric compressor.

The center housing 400 is installed between the motor housing 200 and the rear housing 300. The center housing 400 is formed to have a hollow shape, and four to eight grooves are formed along a circumference of an outer surface of the center housing 400.

That is, the center housing 400 is installed between the motor housing 200 and the rear housing 300 to improve a coupling force of the motor housing 200 and also to minimize deformation of the center housing 400.

The embodiment of the electric compressor of the present invention will be described below.

First, the center housing 400 in which the plurality of grooves are formed is installed at one side of the motor housing 200 in which the mounting lugs 220 are installed.

Next, the rear housing 300 is assembled with one side of the center housing 400 to completely assemble the electric compressor 100.

Here, an assembly order of the electric compressor may be different from the above described order.

An electric compressor according to the present invention has effects in that an amount of vibrations transmitted to a vehicle body can be minimized and a level of driving quietness required as an eco-friendly vehicle can be secured by optimizing a position of a mounting lug of a medium electric compressor.

The above description is only an example describing the technological spirit of the present invention, and various changes and modifications may be made without departing from the spirit and scope of the present invention by those skilled in the art.

Therefore, the embodiments disclosed above and in the accompanying drawings should be considered in a descriptive sense only and not for limiting the technological scope of the present invention. The scope of rights of the present invention is not limited to the embodiments and the accompanying drawings. The scope of protection of the present invention should be interpreted by the appended claims and encompass all equivalents falling within the scope of rights of the appended claims. 

1. An electric compressor comprising: a driving part being a driving source configured to generate a rotating force of the electric compressor, the driving part comprising a stator; a motor housing surrounding the driving part, the motor housing comprising: one or more first mounting lugs installed on an outer surface of the motor housing; and a press fitting portion formed on an inner surface of the motor housing, the stator of the driving part is press fitted into the press fitting portion; a rear housing surrounding a compressing part configured to rotate due to a rotational driving force generated by the driving part so as to compress a refrigerant; and a center housing installed between the motor housing and the rear housing, wherein the first mounting lugs are installed spaced at a first distance from a center of gravity of the electric compressor and overlapping with the press fitting portion.
 2. The electric compressor of claim 1, wherein the first mounting lugs of the motor housing are installed as far away as possible from the center of gravity of the electric compressor within the range of the press fitting portion.
 3. The electric compressor of claim 1, wherein the first mounting lugs of the motor housing are installed to be spaced at a second distance from each other on the outer surface of the motor housing.
 4. The electric compressor of claim 3, wherein the first mounting lugs of the motor housing are symmetrically installed to be collinear with each other on motor housing.
 5. The electric compressor of claim 1, wherein the rear housing comprises: one or more second mounting lugs installed on an outer surface of the rear housing, the mounting lugs being installed to be spaced at a third distance from the center of gravity of the electric compressor.
 6. The electric compressor of claim 5, wherein the second mounting lugs are installed as far away as possible from the center of gravity of the electric compressor.
 7. The electric compressor of claim 5, wherein the mounting lugs of the rear housing are installed to be spaced at a fourth distance from each other on the outer surface of the rear housing.
 8. The electric compressor of claim 7, wherein the second mounting lugs of the rear housing are symmetrically installed to be collinear with each other on the rear housing.
 9. The electric compressor of claim 1, wherein the first mounting lugs of the motor housing are formed to have a cylindrical shape.
 10. The electric compressor of claim 5, wherein the second mounting lugs of the rear housing are formed to have a cylindrical shape. 